Odor-free perm
CA 2034770 C · Owner: Dow Corning Corporation · Inventors: Halloran, Daniel J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed is a method of perming hair by applying to the hair a solution containing an alkali metal or alkaline earth metal siliconate. The siliconates are used in place of typical reducing agents. The perms produce no odor due to the absence of -SH functionality in the perming solutions.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed January 23, 1991 and granted March 14, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 23, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 23, 2013.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.